Acute, pro-contractile effects of prorenin on rat mesenteric arteries

Prorenin and the prorenin receptor ((P)RR) are important, yet controversial, members of the renin-angiotensin-aldosterone system. The ((P)RR) is expressed throughout the body, including the vasculature, however, the direct effect of prorenin on arterial contractility is yet to be determined. Within rat mesenteric arteries, immunostaining and proximity ligation assays were used to determine the interacting partners of (P)RR in freshly isolated vascular smooth muscle cells (VSMCs). Wire myography examined the functional effect of prorenin. Simultaneous changes in [Ca2+ ]i and force were recorded in arteries loaded with Fura-2AM. Spontaneously transient outward currents were recorded via perforated whole-cell patch-clamp configuration in freshly isolated VSMCs. We found that the (P)RR is located within a distance of less than 40 nm from the V-ATPase, caveolin-1, ryanodine receptors, and large conductance Ca2+ -activated K+ channels (BKCa ) in VSMCs. [Ca2+ ]i imaging and isometric tension recordings indicate that 1 nM prorenin enhanced α1-adrenoreceptor-mediated contraction, associated with an increased number of Ca2+ waves, independent of voltage-gated Ca2+ channels activation. Incubation of VSMCs with 1 nM prorenin decreased the amplitude and frequency of spontaneously transient outward currents and attenuated BKCa -mediated relaxation. Inhibition of the V-ATPase with 100 nM bafilomycin prevented prorenin-mediated inhibition of BKCa -derived relaxation. Renin (1 nM) had no effect on BKCa -mediated relaxation. In conclusion, prorenin enhances arterial contractility by inhibition of BKCa and increasing intracellular Ca2+ release. It is likely that this effect is mediated through a local shift in pH upon activation of the (P)RR and stimulation of the V-ATPase.

A multi-disciplinary commentary on preclinical research to investigate vascular contributions to dementia

Although dementia research has been dominated by Alzheimer's disease (AD), most dementia in older people is now recognised to be due to mixed pathologies, usually combining vascular and AD brain pathology. Vascular cognitive impairment (VCI), which encompasses vascular dementia (VaD) is the second most common type of dementia. Models of VCI have been delayed by limited understanding of the underlying aetiology and pathogenesis. This review by a multidisciplinary, diverse (in terms of sex, geography and career stage), cross-institute team provides a perspective on limitations to current VCI models and recommendations for improving translation and reproducibility. We discuss reproducibility, clinical features of VCI and corresponding assessments in models, human pathology, bioinformatics approaches, and data sharing. We offer recommendations for future research, particularly focusing on small vessel disease as a main underpinning disorder.

Macro- and Microvascular Function in Middle-Aged Individuals with Low Cardiovascular Disease Risk

Aims: To investigate the microvascular function in apparently healthy individuals showing signs of early macrovascular endothelial dysfunction. Methods: Healthy participants aged between 30−55 years were recruited for the present study. Baseline measurements included body-mass index (BMI), waist-to-hip ratio (WHR), 24-h blood pressure, as well as fasted venous glucose, triglycerides (TG) and cholesterol (HDL, LDL and total). Brachial artery reactivity was measured using the flow-mediated dilation (FMD) technique and retinal vessel reactivity was assessed by using the Dynamic Retinal Vessel Analyser (DVA) in all individuals. The enrolled participants were separated in two groups, based on either a reduced (group 1: <5%—n = 53) or a normal FMD response (group 2: 7−10%—n = 47). Results: Individuals exhibiting reduced FMD responses showed a reduced baseline-corrected microvascular arterial dilation response to flickering light (p = 0.039). In addition, they also exhibited a reduced arteriolar maximum dilation (p = 0.034), as well as a longer dilation reaction time (p = 0.048) and a lower dilation amplitude (p = 0.042) when compared to those with normal FMD values. Conclusion: In otherwise healthy middle-aged individuals, early signs of vascular dysfunction are reflected simultaneously at both macro- and microvascular levels.

Kynurenine Relaxes Arteries of Normotensive Women and Those With Preeclampsia

Supplemental Digital Content is available in the text.

Rationale:

Activation of the kynurenine pathway of tryptophan catabolism by infection and inflammation contributes to the development of systemic hypotension. Commercially-available kynurenine has direct vasorelaxant effects on arteries from several species and reduces systemic blood pressure when administered to normotensive or hypertensive rats.

Objectives:

To determine whether kynurenine promotes relaxation of human resistance arteries from normotensive and hypertensive pregnant women and to identify the vascular mechanism of its effects.

Methods and Results:

In isolated omental and myometrial resistance arteries from normotensive pregnant women, kynurenine (1 mmol/L) significantly reduced U46619-induced constriction (omentum N=14, P=2.4×10⁻³; myometrium N=21–25, P=2.6×10⁻⁴) and relaxed preconstricted arteries (N=53, P=1.0×10⁻¹¹; N=20, P=8.8×10⁻³). Vasorelaxation persisted following endothelium removal (N=7, P=1.6×10⁻⁴) but was completely prevented by inhibition of large-conductance Ca²⁺-activated K⁺ channels (BK_Ca) channels with iberiotoxin (N=9, P=5.7×10⁻⁴) or paxilline (N=10, P=2.1×10⁻¹⁷). Accordingly, in isolated vascular smooth muscle cells from omental arteries, kynurenine increased the BK_Ca current (n=5–8, P=0.022) and the amplitude of spontaneous transient outward currents (n=6, P=0.031) but did not affect spontaneous transient outward current frequency. Kynurenine also increased Ca²⁺ spark frequency of pressurized omental arteries (n=8, P=0.031). Vasorelaxant effects of kynurenine persisted following inhibition of ryanodine receptors (N=7, P=0.48) but were moderately reduced by inhibition of adenylate cyclase (N=9, P=0.024). In arteries from women with preeclampsia, kynurenine similarly attenuated vasoconstriction (N=15, P=1.3×10⁻⁵) and induced BK_Ca-mediated vasodilation (N=16, P=2.0×10⁻⁴). Vasorelaxation in response to kynurenine and a specific BK_Ca activator, NS11021, was absent in fetal-derived placental resistance arteries in normal pregnancy and preeclampsia.

Conclusions:

Kynurenine dilates systemic arteries from multiple territories via BK_Ca activation. Notably, the vasorelaxatory capacity of kynurenine is preserved in preeclampsia, suggesting this approach may have translational potential for the treatment of hypertension in pregnancy. The data warrant further investigation of the potential to exploit this endogenous vasorelaxant as a new treatment for hypertensive pathologies.

Hypertension and renin-angiotensin system blockers are not associated with expression of angiotensin-converting enzyme 2 (ACE2) in the kidney

AIMS

Angiotensin-converting enzyme 2 (ACE2) is the cellular entry point for severe acute respiratory syndrome coronavirus (SARS-CoV-2)-the cause of coronavirus disease 2019 (COVID-19). However, the effect of renin-angiotensin system (RAS)-inhibition on ACE2 expression in human tissues of key relevance to blood pressure regulation and COVID-19 infection has not previously been reported.

METHODS AND RESULTS

We examined how hypertension, its major metabolic co-phenotypes, and antihypertensive medications relate to ACE2 renal expression using information from up to 436 patients whose kidney transcriptomes were characterized by RNA-sequencing. We further validated some of the key observations in other human tissues and/or a controlled experimental model. Our data reveal increasing expression of ACE2 with age in both human lungs and the kidney. We show no association between renal expression of ACE2 and either hypertension or common types of RAS inhibiting drugs. We demonstrate that renal abundance of ACE2 is positively associated with a biochemical index of kidney function and show a strong enrichment for genes responsible for kidney health and disease in ACE2 co-expression analysis.

CONCLUSION

Our results indicate that neither hypertension nor antihypertensive treatment is likely to alter the expression of the key entry receptor for SARS-CoV-2 in the human kidney. Our data further suggest that in the absence of SARS-CoV-2 infection, kidney ACE2 is most likely nephro-protective but the age-related increase in its expression within lungs and kidneys may be relevant to the risk of SARS-CoV-2 infection.

P6238International cardiovascular disease risk calculators do not identify high risk in young hodgkin lymphoma survivors

Background

Cardiotoxic therapy causes significant morbidity and mortality in patients (pts) treated for Hodgkin lymphoma (HL). Cardiovascular (CVS) risk calculators do not include cancer therapy despite epidemiological data demonstrating increased risk. We have assessed modifiable CVS risk factors and predicted risk of CVS disease in a cohort of HL survivors.

Hypothesis

Cardiovascular risk calculators will not identify high risk in young HL survivors.

Methods

Pts now aged ≤50 treated with doxorubicin and/or radiotherapy (RT) to cardiac tissue for HL >5 years ago were identified. Telephone review of CVS risk factors was offered to pts taking statins or already diagnosed with cerebrovascular or CVS disease. Remaining pts were offered clinical review to assess BMI, blood pressure, cholesterol and HbA1c. Carotid-radial pulse wave velocity (PWV) was measured if available. CVS risk was predicted using international risk calculators (European SCORE, QRISK3, Framingham).

Results

160 eligible pts were identified. Median age was 43 years (26–50) and 52% were female. Median time since treatment was 182 months (61–367). Pts received doxorubicin (n=150), with RT (n=97) or RT alone (n=10). Pts were excluded from study due to severe medical condition (n=8), recurrence (n=1), relocation (n=3) or death (n=1). Data were gathered at clinical review (n=70) or telephone review (n=26). Existing cardiovascular diagnoses included hypertension (n=5), transient ischaemic attack (n=2), valvular disease (n=3), heart failure (n=1), atrial fibrillation (n=2), complete heart block (n=1) and coronary artery disease (n=1).

At clinical review 51% pts had 3 or more modifiable risk factors with a median of 3 (0–5) per pt. Total cholesterol was >5.0 mmol/L in 58% of patients with a median of 5.2 mmol/L (3.2–8.6). Median systolic blood pressure was 125.5 mmHg (103–164). Median body mass index was 26.3 kg/m-2 (18.6–56.1) with 60% of patients classed as overweight or obese.Advice was offered to all smokers (9%), pts that drank alcohol above UK recommended levels (20%) or exercised below the recommended amount (60%). Risk calculators classified 1.4% (QRISK3) and 10% (Framingham) of pts at high risk of CVS disease and 0% (European SCORE) at high risk of CVS mortality. Pulse wave velocity measured in 34 pts was elevated (>8 m/s) in 76% of cases with a median 10.2 m/s (2.3–16.8).

Conclusions

Numerous modifiable CVS risk factors were identified in an HL survivor population known from epidemiological studies to be at high risk of CVS morbidity/mortality. None of the CVS risk calculators identified this high risk. Intriguing data indicate PWV may represent an accessible early indicator of CVS dysfunction. These data prompt comprehensive assessment and management of CVS risk factors in cancer survivors and review of the use of risk calculators in this population.

Acknowledgement/Funding

The Christie NHS Foundation Trust

May Measurement Month 2017: an analysis of blood pressure screening results from the United Kingdom and the Republic of Ireland-Europe

Elevated blood pressure (BP), or hypertension, is a growing burden worldwide, leading to over 10 million deaths each year. May Measurement Month (MMM) is a global initiative aimed at raising awareness of high BP and acting as a stimulus to improving screening programmes worldwide. In the United Kingdom (UK) nearly 1 in 5 people, and in the Republic of Ireland (RoI) 3 out of 10, have hypertension, of which a large proportion remains undiagnosed. An opportunistic cross-sectional survey of volunteers aged ≥18 years was carried out in May 2017. Blood pressure measurement, the definition of hypertension and statistical analysis followed a standardized protocol. Screenings sites in hospitals, universities, shopping centres, workplaces, sports clubs, community centres, GP practices, and pharmacies were set up across the UK and RoI as part of this initiative. Seven thousand seven hundred and fourteen individuals were screened during MMM17. After multiple imputation, 3099 (40.3%) had hypertension. Of individuals not receiving antihypertensive medication, 1406 (23.4%) were hypertensive. Of individuals receiving antihypertensive medication, 682 (40.5%) had uncontrolled BP. MMM17 was the largest BP screening campaign ever undertaken in the UK and RoI. These data prove for the first time that a relatively inexpensive, volunteer based, convenience sampling of screening BP in the community identified two out of five individuals as hypertensive, with one in four not receiving treatment. Of major concern is that these data demonstrate that of those individuals receiving treatment, two out of five still did not have controlled BP.

Engaging parents using web-based feedback on child growth to reduce childhood obesity: a mixed methods study

BACKGROUND

To measure trends in child growth and combat rising levels of obesity, Manchester University NHS Foundation Trust and the University of Manchester have developed Children's Health and Monitoring Programme (CHAMP). CHAMP collects an annual measurement for primary school children (aged 4 to 11) in Manchester, England, and offers feedback of Body Mass Index (BMI) results to parents via a secure website. No similar digital tool exists that both provides high resolution data on the trajectory of child growth and acts as a feedback and monitoring system. This study investigates how effectively this intervention engaged with parents and supported the reduction of childhood obesity.

METHODS

Anonymised CHAMP registration and BMI data (UK1990) were collected between September 2013 and March 2017 from a total of 63,337 children. BMI change over time was compared in matched cohorts of 24,551 children, whose parents had and had not registered with the CHAMP website. Qualitative focus groups and interviews were used to explore perspectives among 29 key informants (parents, school and healthcare professionals) from six schools in Manchester.

RESULTS

Overweight children whose parents had not registered with the CHAMP website gained a median of 0.14 BMI centile between measurements, whilst children of CHAMP-registered parents reduced their BMI by a median of 0.4 centile per year (P = 0.02). Normal weight children of registered parents decreased their BMI by 0.3 centile each year, whilst those not registered increased their BMI by 0.8 centile per year (P = 0.001). There was no significant association between registration and BMI centile change in children already classified as obese (P = 0.34). A qualitative, thematic analysis revealed that the annual measurement programme was widely supported by parents and staff. A range of psychological and behavioural impacts on families were reported as a result of the monitoring and feedback processes, in some cases prompting reflection and monitoring of health and lifestyle choices.

CONCLUSION

These early findings indicate that CHAMP, as both a monitoring system and a digital intervention, could encourage positive lifestyle change and support healthier child growth trajectories.

Modulation of Vascular Reactivity by Perivascular Adipose Tissue (PVAT)

PURPOSE OF REVIEW

In this review, we discuss the role of perivascular adipose tissue (PVAT) in the modulation of vascular contractility and arterial pressure, focusing on the role of the renin-angiotensin-aldosterone system and oxidative stress/inflammation.

RECENT FINDINGS

PVAT possesses a relevant endocrine-paracrine activity, which may be altered in several pathophysiological and clinical conditions. During the last two decades, it has been shown that PVAT may modulate vascular reactivity. It has also been previously demonstrated that inflammation in adipose tissue may be implicated in vascular dysfunction. In particular, adipocytes secrete a number of adipokines with various functions, as well as several vasoactive factors, together with components of the renin-angiotensin system which may act at local or at systemic level. It has been shown that the anti-contractile effect of PVAT is lost in obesity, probably as a consequence of the development of adipocyte hypertrophy, inflammation, and oxidative stress. Adipose tissue dysfunction is interrelated with inflammation and oxidative stress, thus contributing to endothelial dysfunction observed in several pathological and clinical conditions such as obesity and hypertension. Decreased local adiponectin level, macrophage recruitment and infiltration, and activation of renin-angiotensin-aldosterone system could play an important role in this regard.

An unusual case of a brain abscess arising from an odontogenic infection

A brain abscess that originates from an odontogenic infection, although rare, can at times be difficult to diagnose, especially in the context of pain and trismus. We report a rare case of odontogenic infection as a result of an infected maxillary third molar, causing an infratemporal and temporalis collection, resulting in a brain abscess with concurrent cerebritis. This is a clinical case review documenting an uncommon but potentially fatal complication.

Adiponectin induces A20 expression in adipose tissue to confer metabolic benefit

Obesity is a major risk factor for metabolic disease, with white adipose tissue (WAT) inflammation emerging as a key underlying pathology. We detail that mice lacking Reverbα exhibit enhanced fat storage without the predicted increased WAT inflammation or loss of insulin sensitivity. In contrast to most animal models of obesity and obese human patients, Reverbα(-/-) mice exhibit elevated serum adiponectin levels and increased adiponectin secretion from WAT explants in vitro, highlighting a potential anti-inflammatory role of this adipokine in hypertrophic WAT. Indeed, adiponectin was found to suppress primary macrophage responses to lipopolysaccharide and proinflammatory fatty acids, and this suppression depended on glycogen synthase kinase 3β activation and induction of A20. Attenuated inflammatory responses in Reverbα(-/-) WAT depots were associated with tonic elevation of A20 protein and ex vivo shown to depend on A20. We also demonstrate that adipose A20 expression in obese human subjects exhibits a negative correlation with measures of insulin sensitivity. Furthermore, bariatric surgery-induced weight loss was accompanied by enhanced WAT A20 expression, which is positively correlated with increased serum adiponectin and improved metabolic and inflammatory markers, including C-reactive protein. The findings identify A20 as a mediator of adiponectin anti-inflammatory action in WAT and a potential target for mitigating obesity-related pathology.

Impairment of high-density lipoprotein resistance to lipid peroxidation and adipose tissue inflammation in obesity complicated by obstructive sleep apnea

CONTEXT

Obstructive sleep apnea (OSA) complicates morbid obesity and is associated with increased cardiovascular disease incidence. An increase in the circulating markers of chronic inflammation and dysfunctional high-density lipoprotein (HDL) occur in severe obesity.

OBJECTIVE

The objective of the study was to establish whether the effects of obesity on inflammation and HDL dysfunction are more marked when complicated by OSA.

DESIGN AND PATIENTS

Morbidly obese patients (n = 41) were divided into those whose apnea-hypoapnea index (AHI) was more or less than the median value and on the presence of OSA [OSA and no OSA (nOSA) groups]. We studied the antioxidant function of HDL and measured serum paraoxonase 1 (PON1) activity, TNFα, and intercellular adhesion molecule 1 (ICAM-1) levels in these patients. In a subset of 19 patients, we immunostained gluteal sc adipose tissue (SAT) for TNFα, macrophages, and measured adipocyte size.

RESULTS

HDL lipid peroxide levels were higher and serum PON1 activity was lower in the high AHI group vs the low AHI group (P < .05 and P < .0001, respectively) and in the OSA group vs the nOSA group (P = .005 and P < .05, respectively). Serum TNFα and ICAM-1 levels and TNFα immunostaining in SAT increased with the severity of OSA. Serum PON1 activity was inversely correlated with AHI (r = -0.41, P < .03) in the OSA group. TNFα expression in SAT directly correlated with AHI (r = 0.53, P < .03) in the subset of 19 patients from whom a biopsy was obtained.

CONCLUSION

Increased serum TNFα, ICAM-1, and TNFα expression in SAT provide a mechanistic basis for enhanced inflammation in patients with OSA. Decreased serum PON1 activity, impaired HDL antioxidant function, and increased adipose tissue inflammation in these patients could be a mechanism for HDL and endothelial dysfunction.

Relationship of endothelial function and atherosclerosis to treatment response in late-life depression

OBJECTIVE

Treatment response in late-life depression has been linked to cerebrovascular disease notably via the vascular depression hypothesis. This study investigated the relationship between endothelial function and atherosclerosis and treatment response to antidepressant monotherapy.

METHODS

Twenty five patients with late-life depression were compared with 21 non-depressed control subjects in a case control study. Nine of the depressed subjects were responders to antidepressant monotherapy and 16 were not. Vascular measures included assessment of carotid intima media thickness (IMT) representing atherosclerosis and biopsied small artery dilatation to acetylcholine to assess endothelial function in a subset of subjects.

RESULTS

There were no group differences in vascular risks or sociodemographic variables. There was a significant group difference (responders versus non-responders versus controls) on both IMT and endothelial function (p < 0.01 and p < 0.05, respectively) with a significant difference between controls and non-responders (p < 0.001) on IMT and between controls and responders (p < 0.05) and control versus non-responders (p < 0.05) on endothelial function but no significant difference between responders and non-responders. On both IMT and endothelial function, there was a gradient across groups, with control subjects having best vascular structure or function, non-responders worse and responders in-between.

CONCLUSIONS

The results are consistent with a hypothesis that poorer antidepressant response in later life depressive disorder may be linked to an underlying vascular dysfunction and pathology. The study is small, and the results require replication but if confirmed, trials with vasoprotective medication aimed at improving vascular function in order to alter the prognosis of late-life depression would be a rational development.

Transnasal K-wire to stabilise a complex zygomatic fracture: a forgotten method of fixation

Zygomatic complex fractures make up approximately 60% of facial fractures. The vast majority treated surgically use titanium miniplates. These require longer operating times and facial incisions to access the fracture. The use of a K-wire was first described 60 years ago. As a new generation of surgeons emerges, it is important to be aware of the various techniques available to increase their surgical armamentarium. One of its benefits is that it has a significantly reduced operative time and does not require any incisions.

Perivascular adipose tissue from human systemic and coronary vessels: the emergence of a new pharmacotherapeutic target

Fat cells or adipocytes are distributed ubiquitously throughout the body and are often regarded purely as energy stores. However, recently it has become clear that these adipocytes are engine rooms producing large numbers of metabolically active substances with both endocrine and paracrine actions. White adipocytes surround almost every blood vessel in the human body and are collectively termed perivascular adipose tissue (PVAT). It is now well recognized that PVAT not only provides mechanical support for any blood vessels it invests, but also secretes vasoactive and metabolically essential cytokines known as adipokines, which regulate vascular function. The emergence of obesity as a major challenge to our healthcare systems has contributed to the growing interest in adipocyte dysfunction with a view to discovering new pharmacotherapeutic agents to help rescue compromised PVAT function. Very few PVAT studies have been carried out on human tissue. This review will discuss these and the hypotheses generated from such research, as well as highlight the most significant and clinically relevant animal studies showing the most pharmacological promise.

LINKED ARTICLES

This article is part of a themed section on Fat and Vascular Responsiveness. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-3.

Small-dense LDL and LDL glycation in metabolic syndrome and in statin-treated and non-statin-treated type 2 diabetes

Small-dense LDL (SD-LDL) has been particularly implicated in atherosclerosis. It has previously been reported that in non-diabetic people SD-LDL is preferentially glycated. The distribution of glycated apolipoprotein B (glyc-apoB) in lipoproteins in metabolic syndrome (MS) and in type 2 diabetes has not previously been studied. Plasma apoB and glyc-apoB were determined in different apoB-containing lipoproteins including buoyant and SD-LDL in MS (n=18) and type 2 diabetes (DM) [n=48; 12 statin-untreated (DM-S) and 36 statin-treated (DM+S)]. Plasma glyc-apoB was 5.6 ± 0.9, 3.5 ± 0.5 and 4.0 ± 0.2 mg/dl in DM-S, DM+S and MS, respectively. The glycated proportion of SD-LDL-apoB was greater than buoyant LDL in all groups. SD-LDL contributed most to plasma glyc-apoB in DM-S, because SD-LDL-apoB was higher in DM-S than in MS and DM+S (p < 0.001). Plasma glyc-apoB correlated with SD-LDL-apoB (r=0.74, p < 0.0001 in diabetes and r=0.53, p < 0.001 in MS), but not with HbA(1c). SD-LDL is preferentially glycated in type 2 diabetes and MS. Its concentration is a stronger determinant of plasma glycapoB than glycaemia. Statin-induced changes in its level may be important in decreasing apoB glycation in diabetes. These findings may explain the small effect of improving glycaemia relative to statin treatment in reducing atherosclerosis risk in type 2 diabetes and the increased risk in MS even before the onset of type 2 diabetes.

Diabetic cardiomyopathy--a distinct disease?

Diabetic individuals have a significantly increased likelihood of developing cardiovascular disease. Whilst part of this association is explained by the presence of concomitant risk factors, large epidemiological studies have consistently reported diabetes as a strong risk factor for the development of heart failure after adjusting for such covariates. This has resulted in the notion that there is a distinct cardiomyopathy specific to diabetes, termed 'diabetic cardiomyopathy'. The natural history is characterized by a latent subclinical period, during which there is evidence of diastolic dysfunction and left ventricular hypertrophy, before overt clinical deterioration and systolic failure ensue. These clinical findings have been supported by a growing body of experimental data which support the notion that diabetes inflicts a direct insult to the myocardium, with cellular, structural and functional changes manifest as the diabetic myocardial phenotype. Several of these mechanisms appear to work in unison, forming complicated reciprocal pathways of disease. Reactive oxygen species and alterations in intracellular calcium homeostasis appear to play significant roles in many of these mechanisms. Determining the hierarchy of this cascade of disease will allow identification of the pathological trigger most responsible for disease. Translational research in this field is currently hindered by a lack of clinical studies and intervention trials specifically in patients with diabetic cardiomyopathy. Future clinical and experimental studies of accurate models of diabetic cardiomyopathy should help to define the true aetiology and lead to the development of specific pharmacotherapies for this condition, ultimately reducing the increased cardiovascular morbidity and mortality in diabetic patients.

Vascular remodeling: implications for small artery function and target organ damage

At the level of the small artery, essential hypertension is associated with eutrophic inward remodeling. This involves reduction in lumen diameter by an increase in wall thickness. Previously thought to involve either hypertrophy or hyperplasia of the vascular smooth muscle cells in the media, it is now felt to be mediated by a functional property of the wall: myogenic tone. This is the ability of an artery to contract in response to an increase in intraluminal pressure. This autoregulatory function is also vital to ensure stabilisation of distal capillary pressures and so prevent, or limit, organ damage. Indeed in any animal model studied, when myogenic autoregulation is affected, target organ damage ensues. We have also observed, in two studies, that when myogenic autoregulation is damaged in the context of hypertension, eutrophic remodeling is replaced by an outward growth of the arterial wall with preservation of lumen diameter. This is called hypertrophic remodeling and, independently, has been observed by a number of groups in small arteries from patients with type 2 diabetes. We believe that this is a key reason for the unique propensity to hypertensive injury seen in patients with diabetes. We also discuss the significance of integrins, transmembrane proteins with wide ranging functions; from initiation of cell migration to intracellular signalling. Two particular integrins, alpha5beta1 and alphanubeta3, have been found to be necessary for both normal myogenic autoregulation and eutrophic remodeling and the possibility that damage to these may occur in diabetes is examined.

Intravenous infusions in hyperbaric chambers: effect of compression on syringe function

Haemodynamic instability is a recognised phenomenon in critically ill patients undergoing hyperbaric therapy. Instability may result from the effects of ambient pressure on the cardiovascular system, devices involved in infusion of drugs and fluids, or a combination of the two. The effect of hyperbaric pressure on air-containing spaces in syringes has not been previously measured. We connected 60-ml syringes (Terumo Corporation, Tokyo, Japan) containing coloured water to low volume extensions via three-way taps. We examined the effect of pressurisation to 2.4 and 2.8 atmospheres absolute (ATA) on the syringes by measuring the displacement of the coloured water in the low volume extension set. There was compression of air spaces within the syringe causing retrograde flow of fluid within the low volume extension set. The mean (95% CI) change in volume was 154 (141-168) microl at 2.4 ATA, and 197 (183-212) microl at 2.8 ATA (both p < 0.0001). We conclude that hyperbaric exposure may cause clinically significant changes in syringe function at infusion rates < 100 ml. h(-1).

Are consecutive nightly recordings required for valid evaluation of sleep-associated erections?

We questioned the need for more than one RigiScan recording for accurate assessment of sleep-associated penile erections and determine the necessity of consecutive nightly recordings for valid evaluation of sleep-associated erections. Men complaining of erectile dysfunction (ED) and referred to RigiScan evaluation for the first time participated. Recordings were performed at the patient's home during two consecutive nights, and data on test time, number of erections, erection duration, minimal and maximal base and tip tumescence and rigidity were retrieved for both nights. Normal erectile function was defined with the recording of at least one erection (70 out of 100% tip rigidity lasting for at least 10 min during either night). The main outcome measures were RigiScan recordings. Group 1 consisted of 29 men (mean age 42.4+/-13.8 years, range 22-71) who had normal erections, all during the first night. Group 2 consisted of 26 men (mean age 48.6+/-13.5 years, range 25-70) who failed to fulfill both criteria for normal erection. In Group 2, only the values for penile base rigidity and erection duration were normal during the first night: the parameters of maximal base tumescence, tip rigidity, number of effective erections and duration of effective erections that were impaired during the first night were significantly worse (P<0.01) during the second night. The required information for the diagnosis of psychogenic ED was obtained during the first night in >50% of the participants. Men with normal erections during the first night can be spared the inconvenience and cost of re-testing. Consecutive night recording should be reserved for patients whose recorded data during the first night did not fulfill the criteria for normal erection.

Sexual dysfunction in women partners of men with erectile dysfunction

We evaluated 113 female partners of men with erectile dysfunction (ED) attending a sexual dysfunction clinic in order to define sexual dysfunction among these women. In all, 51 (45%) women denied having any sexual dysfunction. The other 62 (55%) responded to questions classifying their complaint(s) according to the international classification of female sexual dysfunction (FSD) in the following topics (40/62, 65%, reported having more than one problem): decreased sexual desire (n=35, 56%), sexual aversion (none), arousal (n=23, 37%) and orgasmic disorders (n=39, 63%), dyspareunia (n=19, 31%), vaginismus (n=3, 5%), and noncoital sexual pain (none). Many female partners of men with ED report having some form of sexual disorder, mostly orgasmic problems and decreased sexual desire. Therefore, for optimal outcome of ED treatment, evaluation and treatment of male and FSD should be addressed as one unit within the context of the couple, and be incorporated into one clinic of sexual medicine.

Anti-CCP antibodies measured at disease onset help identify seronegative rheumatoid arthritis and predict radiological and functional outcome

OBJECTIVE

Anti-cyclic citrullinated peptide (anti-CCP) antibodies have been identified as highly specific for rheumatoid arthritis (RA). Studies suggest an association with radiographic outcome. The aims of this study were to assess the diagnostic and prognostic utility of the second-generation anti-CCP(2) test in a large cohort of early RA patients compared with connective tissue disease (CTD) controls.

METHODS

One hundred and eighty-two patients with RA and 121 patients with CTD were recruited. All RA patients had less than 24 months of symptoms and had CRP, rheumatoid factor (RF), HLA typing (SE) and anti-CCP(2) antibodies measured at baseline. Function was assessed using the Health Assessment Questionnaire (HAQ) and X-rays performed at 0, 12 and 24 months.

RESULTS

The anti-CCP(2) antibody test demonstrated a specificity of 91% and sensitivity of 81% for RA when compared with controls. In RF-negative patients, specificity was 92% and sensitivity 60%. Baseline demographics of the RA cohort showed mean age 57 yr, mean symptom duration 7 months, 63% RF-positive patients, 72% SE-positive, 81% CCP-positive and 21% erosive. The only predictor of change in Larsen score from 0 to 24 months in the cohort was the presence of the shared epitope (P<0.05) and in the RF-negative subgroup it was CCP(2) antibody titre >100 (P<0.05). Baseline HAQ was the only significant predictor of HAQ at 24 months, but in the RF-negative subgroup CCP(2) antibody titre >100 predicted a poor functional response at 24 months (P<0.05).

CONCLUSIONS

This study confirms the diagnostic utility of anti-CCP(2) antibodies in early RA, particularly in seronegative patients, in whom anti-CCP(2) positivity also conferred prognostic utility for radiographic and functional outcomes.

Infliximab in combination with methotrexate in active ankylosing spondylitis: a clinical and imaging study

OBJECTIVE

To examine the efficacy and safety of infliximab combined with methotrexate compared with methotrexate alone in the treatment of ankylosing spondylitis (AS) using MRI and DXA to monitor its impact on bone.

METHODS

In this single centre study 42 subjects with active AS were treated with methotrexate and were randomly assigned, in a ratio of 2:1, to receive five infusions of either 5 mg/kg infliximab or placebo over 30 weeks. The primary outcome was improvement in disease activity as shown by the BASDAI at week 30. MRI was used to assess the effect of treatments on sacroiliac and spinal enthesitis/osteitis and DXA to monitor bone mineral density.

RESULTS

Both therapeutic agents were well tolerated with no dropouts due to adverse events. A significantly greater improvement in mean BASDAI score was seen in the infliximab arm at week 10 (p = 0.017) than in the placebo arm, but this was not maintained by week 30 (p = 0.195), 8 weeks after the last infusion, at which stage disease flares were reported by some subjects. MRI showed that the mean number of lesions resolving for each subject from week 0 to week 30 was significantly greater in the combination group than in the methotrexate monotherapy group (p = 0.016).

CONCLUSIONS

Infliximab in combination with methotrexate was a safe and efficacious treatment in AS over 6 months and was associated with significant regression in enthesitis/osteitis as determined by MRI. However, disease flares were reported 8 weeks after the last infusion, indicating that addition of methotrexate failed to extend the infliximab dosing interval.

Very early treatment with infliximab in addition to methotrexate in early, poor-prognosis rheumatoid arthritis reduces magnetic resonance imaging evidence of synovitis and damage, with sustained benefit after infliximab withdrawal: results from a twelve-month randomized, double-blind, placebo-controlled trial

OBJECTIVE

Anti-tumor necrosis factor alpha agents are among the most effective therapies for rheumatoid arthritis (RA). However, their optimal use is yet to be determined. This 12-month double-blind study attempted remission induction using standard therapy with or without infliximab in patients with early, poor-prognosis RA. The primary end point was synovitis (measured by magnetic resonance imaging [MRI]). Clinical observations continued to 24 months.

METHODS

All patients had fewer than 12 months of symptoms. Assessments included full metrologic evaluation, laboratory tests, radiographs, functional evaluation using the Health Assessment Questionnaire (HAQ), and quality of life measurement using the RA Quality of Life (RAQoL) questionnaire. MRI was performed at 0, 4, 14, and 54 weeks; MR images were scored blindly. Patients received methotrexate (MTX) and were randomized to receive either infliximab or placebo for 12 months.

RESULTS

Twenty patients were recruited (mean age 52 years, mean symptom duration 6 months, mean C-reactive protein level 42 mg/liter, and 65% rheumatoid factor positive). At 1 year, all MRI scores were significantly better, with no new erosions in the infliximab plus MTX group; a greater percentage of infliximab plus MTX-treated patients fulfilled the American College of Rheumatology (ACR) 50% and 70% improvement criteria (78% versus 40% in the placebo plus MTX group and 67% versus 30%, respectively) and had a greater functional benefit (P < 0.05 for all comparisons). Importantly, at 1 year after stopping induction therapy, response was sustained in 70% of the patients in the infliximab plus MTX group, with a median Disease Activity Score in 28 joints (DAS28) of 2.05 (remission range). At 2 years, there were no significant between-group differences in the DAS28, ACR response, or radiographic scores, but differences in the HAQ and RAQoL scores were maintained (P < 0.05).

CONCLUSION

Remission induction with infliximab plus MTX provided a significant reduction in MRI evidence of synovitis and erosions at 1 year. At 2 years, functional and quality of life benefits were sustained, despite withdrawal of infliximab therapy. These data may have significant implications for the optimal use of expensive biologic therapies.

Per urethra insertion of a through-and-through safety guide wire using a dual-lumen ureteral catheter during percutaneous nephrolithotripsy

BACKGROUND

The second ("safety") of two guide wires is commonly inserted antegradely in percutaneous nephrolithotripsy (PCNL). We describe the retrograde insertion of a through-and-through safety guide wire during PCNL.

METHODS

After inserting a percutaneous nephrostomy 1 day earlier, a guide wire was introduced through the nephrostomy tube to the bladder and pulled out through the urethral meatus via a cystoscope and grasper. The tube was removed, leaving the wire positioned from the flank to the meatus. A dual-lumen catheter was introduced retrogradely through the urethra over the wire, up to the nephrostomy incision. The safety guide wire was introduced retrogradely through the catheter's other port.

RESULTS

This procedure succeeded in 9 of 10 patients: the exception was very obese and the catheter was too short to reach the incision in the flank.

CONCLUSION

Using a dual-lumen catheter allows quick and simple retrograde insertion of a safety guide wire during PCNL.

The use of temozolomide in recurrent malignant gliomas

Gliomas are the most common primary intracerebral tumours and over 60% of these are malignant. Standard treatment in the UK for patients with a good performance status consists of surgery and postoperative radiotherapy, however, recurrence is almost inevitable. Treatment of recurrent malignant gliomas (MG) is limited to further surgery, chemotherapy and novel biological therapies. The response rate to standard chemotherapy protocols for recurrent MG is less than 30%. Temozolomide (Temodar-US, Temodal-Rest of World) is an oral alkylating agent with a similar chemical structure to dacarbazine, and has recently been licensed in the UK for second line treatment of recurrent MG. Several phase II studies and one randomised trial suggest that Temozolomide improves time to progression and quality of life but not overall survival. The drug is well tolerated with dose limiting myelosuppression and thrombocytopenia occurring in less than 10% of patients at current dosage schedules. A randomised trial comparing Temozolomide with best first line adjuvant chemotherapy (PCV) is about to start recruiting patients. Further clinical studies investigating its role in neoadjuvant treatment or in combination with radiotherapy or other chemotherapeutic approaches are ongoing.

Does local hyperthermia affect metastasis of a human prostate carcinoma grown in athymic nude mice?

PRIMARY OBJECTIVE

This study investigated whether local hyperthermia increases metastasis of prostate carcinoma xenografts in athymic nude mice.

RESEARCH DESIGN AND METHODS

Human prostate carcinoma cells (1-LN-PC-3-1A) were injected into the animal's thigh. Mice were randomly divided into those treated with local hyperthermia (43 degrees C for 45 min, tumour volume 100 or 200 mm(3)) and untreated controls, and sacrificed when the tumour volume reached 500 mm(3).

MAIN OUTCOMES AND RESULTS

Histological evaluation (hematoxylin and eosin staining) of lymph nodes showed metastases in 20/21 hyperthermia-treated and 17/21 control mice. Lymph node involvement, tumour weight at sacrifice, and tumour growth rate were not significantly different between groups.

CONCLUSION

Single local hyperthermia treatment had no effect on lymph node metastatic spread in this model.

Sildenafil versus the vacuum erection device: patient preference

PURPOSE

We evaluated the preference of patients with erectile dysfunction who had been effectively treated with a vacuum erection device and then switched to sildenafil.

MATERIALS AND METHODS

A total of 52 patients with erectile dysfunction who achieved satisfactory erectile function according to the International Index of Erectile Function (IIEF) while using a vacuum erection device were switched to an increasing dose of sildenafil (range 25 to 100 mg.) until satisfactory erection was maintained at least twice a week for at least 1 month. The 2 treatment methods were not used concomitantly. A total of 36 patients with a mean age of 59 years (range 35 to 77) who claimed to have achieved satisfactory erections with a vacuum erection device and sildenafil reported their preference to continue sildenafil or resume the use of a vacuum erection device, reasons for the choice and any adverse side effects.

RESULTS

Of the 36 participants in whom the efficacy of sildenafil was similar to that of a vacuum erection device according to the IIEF scores (mean plus or minus standard deviation 61.6 +/- 10.4 and 62.5 +/- 6, respectively), 12 (33.3%) decided to resume use of a vacuum erection device (group 1) while 24 (66.6%) preferred to continue sildenafil (group 2). There were no statistically significant differences between the groups regarding patient age or the etiology and duration of erectile dysfunction. The increase in the IIEF score while using a vacuum erection device was higher in group 1 than 2, with a mean of 66.75 versus 60.4, respectively (p = 0.002). The adverse side effects of sildenafil were the main reasons for preferring a vacuum erection device. Fewer ejaculatory difficulties, efficacy, comfort and ease of use were the main reasons for choosing sildenafil.

CONCLUSIONS

Even in an era of effective oral medication, the vacuum erection device remains a preferred treatment option for a substantial number of patients with erectile dysfunction.

The effect of methylene blue on histological damage after spermatic cord torsion in a rat model

OBJECTIVE

To investigate, in a rat model, whether methylene blue (a free-radical scavenger) is effective in alleviating the histological testicular damage caused by reperfusion after spermatic cord torsion.

MATERIALS AND METHODS

Male Wistar rats underwent a clockwise 720 degrees left spermatic cord torsion lasting 3 h; they were then randomly assigned to treatment and control groups. In the treated group, 2 mg/kg methylene blue was injected intraperitoneally 20 min before the cord was untwisted, and an additional 1 mg/kg injected into the penile vein 1--2 min beforehand. After 14 days, the left testicle was removed and assessed histologically. The control group was not treated.

RESULTS

Thirty-three rats in the treatment group and 35 untreated controls were suitable for evaluation. Treatment with methylene blue was not significantly predictive of histological damage; the colour of the testis before detorsion was not correlated with histological damage.

CONCLUSION

Anti-oxidant treatment with methylene blue had no palliative effect on the histological changes after torsion and detorsion of the spermatic cord in this rat model.

Estrogen and progesterone receptors in murine models of systemic lupus erythematosus

Estrogens are believed to play a role in the etiology of both human and murine systemic lupus erythematosus (lupus; SLE), presumably through the agency of their cellular receptor proteins. There is now considerable interest in the molecular mechanism of action of estrogens in immune tissues, particularly with regard to autoimmune disorders, which are generally more prevalent in women. In this laboratory, an attempt is being made to characterize estrogen receptors in murine models of SLE and to try and relate this to estrogen receptor function in vivo. The initial aim was to compare binding properties of estrogen receptors in brain, reproductive and immune tissues of BALB/c and MRL/MP-lpr/lpr mice. The latter strain spontaneously develops an autoimmune disease resembling human systemic lupus erythematosus (lupus; SLE). It is hypothesized that estradiol, through its receptors, mediates the progression of murine SLE, and that in autoimmune disease, the estrogen receptor is functionally and/or structurally changed. Initial studies suggest that there are differences in estrogen receptors between BALB/c mice, which do not get autoimmune disease, and two strains that do, MRL/MP-lpr/lpr and NZB/W mice. In MRL mice, these differences may be reflected in impaired priming of the progesterone receptor.

Clinical efficacy of sildenafil in patients on chronic dialysis

PURPOSE

We evaluate the clinical efficacy of sildenafil citrate for patients who are on chronic dialysis and who have concomitant erectile dysfunction.

MATERIALS AND METHODS

A total of 35 men (mean age 60.7 years) on dialysis and with erectile dysfunction of various etiologies were administered 25 to 100 mg sildenafil for at least 6 months. The International Index of Erectile Function questionnaire (IIEF), a global assessment question and partner satisfaction question were used to evaluate sildenafil efficacy. Patients also reported any adverse events that occurred during treatment.

RESULTS

Treatment was effective for 28 of the 35 (80%) patients according to the results of the IIEF and global assessment questions. Partner satisfaction correlated with the IIEF overall response (0.79) and global assessment question results (0.86). No correlation was found between sildenafil failure and patient age, the etiology of erectile dysfunction, duration of erectile dysfunction, prior treatments, testosterone and prolactin blood levels, and the duration and etiology of renal failure. Of the 35 patients sildenafil was stopped due to intolerable headaches in 3 and because of lack of efficacy in 7.

CONCLUSIONS

Sildenafil is an effective and safe treatment for erectile dysfunction in most patients on chronic dialysis.

Alleviating constipation in the elderly improves lower urinary tract symptoms

BACKGROUND

Constipation and lower urinary tract symptoms (LUTS) very frequently occur in the elderly, and several reports have suggested that dysfunction in either one of these systems may affect the other. Most studies correlating rectal and bladder dysfunction, however, have been carried out in children or young women.

OBJECTIVE

To examine the effect of alleviating constipation on LUTS in the elderly.

METHODS

Fifty-two patients aged 65-89 (mean 72 +/- 13) years with chronic constipation and LUTS participated in this prospective cohort study. Before treatment of constipation was initiated and on their monthly visits, patients completed a questionnaire regarding their constipation pattern, urinary symptoms, sexual function and mood, and underwent urinalysis. Urinary tract anatomy and residual urine were evaluated by abdominal ultrasound at the commencement and completion of the study. Patients were followed up for 4 months.

RESULTS

Treatment of constipation increased the number of weekly defecations from 1.5 +/- 0.9 to 4.7 +/- 1.2 (p < 0.001). Patients spent less time on the toilet (25 +/- 2.1 versus 63 +/- 1.9 min, p < 0.0001). Fewer patients reported urgency (16 versus 34, p < 0.001), frequency (25 versus 47, p < 0.001) and burning sensation during urination (6 versus 17, p < 0.05). There was improvement in the scoring of urgency, frequency and burning sensation (from a baseline of 52 to 126, 131 and 95, respectively, p < 0.001). Urinary stream disturbances improved in 32 of the 52 patients (p < 0.001). Residual urine volume decreased from 85 +/- 39.5 to 30 +/- 22.56 ml (p < 0.001). There was also a significant decrease in the number of patients with bacteriurial events (5 versus 17, p < 0.001), and an improvement in sexual activity and mood (p < 0.05).

CONCLUSIONS

Our data demonstrated that medical relief of constipation significantly improves LUTS in the elderly which, in turn, improves the patient's mood, sexual activity and quality of life.

Catecholamine sensitivity in the rat femoral artery after microvascular anastomosis

Tissue can demonstrate vasospastic instability after microvascular anastomosis. This study investigates the in vitro effect of increasing concentrations of phenylephrine on the rat femoral artery after microvascular anastomosis. Bilateral groin flaps based on the inferior epigastric artery were raised on 55 Wistar male rats. On the test side, a microvascular anastomosis was performed, but not on the control side. On days 2-12 postoperatively, the rats were sacrificed and the femoral arteries harvested and suspended in increasing concentrations of phenylephrine. The vascular tone on the test and control sides were recorded and compared. Increased sensitivity was found on the test side as compared with the control side (P = 0.000). This supersensitivity to phenylephrine was blocked by the addition of phentolamine and it is believed to be the result of sympathetic denervation, which occurs when the sympathetic fibers are cut during the harvesting of the flap. The resulting vascular instability is believed to contribute to flap failure.

Predicting penile size during erection

The aim of this prospective study was to identify clinical and engineering parameters of the flaccid penis for prediction of penile size during erection. Dorsal and ventral penile lengths, as well as base and tip circumferences were measured in flaccid states, gently stretched states and at full erection resulting from intracavernosal injection of prostaglandin E1 in 55 patients. The forces required to stretch the penis were measured by a specially designed gauge and regression relationships of the measured dimensions were calculated. An engineering model was developed to analyze differences between results obtained during stretching and erection, as well as to approximate the optimal force values which should be applied during the stretching part of the clinical evaluation of penile size. The ratio between the flaccid to stretched penile lengths was shown to be the best predictor for the ventral elongation from flaccid to erect penile lengths. The engineering analysis predicted that a minimal tension force of approximately 450 g during stretching of the penis is required to reach the potential erection length. The stretching forces exerted by the urologist in the clinical setting were experimentally shown to be significantly (P<0.01) less than this value. The values of the relative and absolute elongations of the stretched penis at its ventral aspect provide reliable estimations of its potential maximal elongation during erection. The model designed for this study may obviate the use of intracavernosal injections for estimating penile length during erection.